The present invention relates to a rotor configuration for an electrical machine and particularly to spacers for axially spacing enclosure rings and annular shields about the pole faces and field winding modules of an electrical machine.
In a particular electrical machine, a rotor configuration includes a multi-pole rotor core for rotation about an axis. A plurality of field winding modules are respectively disposed about each pole of the multi-pole rotor core and an enclosure is disposed over the field winding modules to contain the latter about the rotor core. A magnetic shield is disposed about and between the field winding modules and the enclosure.
The enclosure, as well as the shield, forms part of a containment system for the windings. It will be appreciated that the windings in the rotor require cooling and typically a cooling medium flows through defined passages in the rotor and exits into the air gap between the rotor and the stator. Part of the enclosure includes rings. Accordingly, there is a need to maintain the enclosure rings about the field winding modules axially positioned relative to one another and along the rotor shaft to provide well-defined locations for radial discharge of the cooling medium, as well as to enable electrical connection of the amortisseur shield segments, while simultaneously affording assembly aids to render the rotor architecture easier to assemble.